A workshop has a saw so loud that everyone near it must wear ear defenders. There is another answer: buy a quieter saw. One answer changes the people. The other changes the hazard. Safety people rank every answer to a hazard on a ladder, and the ladder always runs the same way.
Get rid of it→Swap it→Keep people away→Rules and training→Protective gear
From best to last. Get rid of the hazard. Swap it for something less harmful. Keep people away from it, with a guard, a fence, or a fan that pulls the fumes out. Change how people work, with rules and training. Give people protective gear. Each rung down is weaker than the one above.
Protective gear
↓→
Which rung?
Where does protective gear sit on the ladder?
Last.
Right. Gear is the answer you reach for when the higher rungs have done what they can. It is the most visible answer, which is why people picture it first.
First.
Not yet. It is the first thing people picture, because a helmet is easy to see and a quieter saw is not. On the ladder it is last, because it fixes the person and not the hazard.
In the middle.
Not yet. The middle rung is keeping people away: guards and fences. Gear sits below rules and training, at the bottom.
A guardeveryone, always
vsvs
A maskone person, while worn
Protective gear comes last because it protects one person, only while it is worn, only if it fits, and only if it is the right kind. A guard on a machine works for everyone, every shift, whether or not anybody remembers. The higher rungs do not depend on a person getting it right every time.
Move the control up and down the ladder. Picture a hazard whose risk starts at 100, and made-up round numbers for how much each rung leaves behind.
Risk before100 out of 100
Risk left0 out of 100
Get rid of itGet rid of it: of a risk that started at 100, nothing is left. The hazard is gone, so there is nothing left to go wrong.
Risk before100 out of 100
Risk left20 out of 100
Swap itSwap it: of a risk that started at 100, about 20 is left. A less harmful thing is there instead; the harm it can do is smaller, but not nothing.
Risk before100 out of 100
Risk left40 out of 100
Keep people awayKeep people away: of a risk that started at 100, about 40 is left. The hazard is still there and people are kept from it; the guard works for everyone, every shift, unless it is removed.
Risk before100 out of 100
Risk left70 out of 100
Rules and trainingRules and training: of a risk that started at 100, about 70 is left. The hazard and the people are both still there, and the rule holds only when every person follows it every time.
Risk before100 out of 100
Risk left85 out of 100
Protective gearProtective gear: of a risk that started at 100, about 85 is left. Everything is still there; the gear protects one person, while it is worn, if it fits, if it is the right kind.
Rules and training leave 70 of the 100. Why so much, when every worker was trained?
The number is wrong. A trained worker is as safe as a guarded machine.
Not yet. Training changes the person and leaves the hazard as it was. A guard is there on the bad day too; the training has to be remembered on it.
A rule works only when every person follows it every time, and people forget, hurry, and are new.
Right. The hazard is untouched and the people are still beside it. The rule is a thin layer between them, and it has a hole every time somebody is tired.
Because training is expensive.
Not yet. Cost is not what the number measures. It measures how much harm can still happen, and a trained person beside an unguarded blade can still be hurt.
Move the control.
A bakery fits a guard over the blades of its mixer. Tap the rung that is.
Tap the part of the picture that answers it.
Get rid of it→Swap it→Keep people away→Rules and training→Protective gear
Keep people away
Right. A guard leaves the blades where they are and puts metal between them and a hand. That is the middle rung: the hazard stays, the people are kept from it.
Get rid of it
Not yet. Getting rid of the hazard would mean no blades at all, and a mixer needs them. The guard keeps the blades and keeps hands out.
Swap it
Not yet. Swapping would be a different mixer that does the job with less harm. This is the same mixer with a cover, which is keeping people away.
Rules and training
Not yet. A rule would be switch off before you reach in. The guard does not ask anyone to remember anything, which is why it sits above rules.
Protective gear
Not yet. Gear would be a cut-proof glove on each baker. The guard protects every hand that comes near, worn or not.
Each card is an answer to a paint shop's fumes. What does it change?
One card at a time. Tap the pile it belongs to.
Card 1 of 6
Buy water-based paint instead of solvent paint.
Fit a fan that pulls the fumes out through the wall.
Make everyone wear a mask when spraying.
Stop using that chemical altogether.
Put the spraying inside a closed booth with its own extraction.
Train staff to spray for twenty minutes, then take a break outside.
Buy water-based paint instead of solvent paint. → The hazard
Not yet. The hazard. The paint itself is swapped for one that gives off less; nothing about the room or the painter changed.
Fit a fan that pulls the fumes out through the wall. → The place
Not yet. The place. The paint and the painter are as they were; the room now carries the fumes away before they reach a face.
Make everyone wear a mask when spraying. → The person
Not yet. The person. The fumes are still made and still fill the room; each painter carries their own protection, while it is on.
Stop using that chemical altogether. → The hazard
Not yet. The hazard, and the top of the ladder. A chemical that is not there cannot be breathed, whatever the room and the people do.
Put the spraying inside a closed booth with its own extraction. → The place
Not yet. The place. The booth is a guard for a gas: the fumes are made inside it and taken away inside it, whoever is working.
Train staff to spray for twenty minutes, then take a break outside. → The person
Not yet. The person. It is a rule about how people work, and it holds only while every painter watches the clock.
rungs 1 and 2The hazard
↓→
rung 3The place
↓→
rungs 4 and 5The person
Right. The top two rungs change the hazard. The middle one changes the place, so the hazard and the people are kept apart. The bottom two change the person, and the person has to get it right every time.
Real workplaces use several rungs at once. A quieter saw, then a screen round it, then a rule about how long anyone stands there, then ear defenders for what is left. The ladder does not say gear is useless. It says gear is for the risk the higher rungs could not reach.
Used needles
↓→
Which answer?
Hospital staff keep pricking themselves on used needles. Which answer is highest on the ladder?
A poster reminding staff to be careful.
Not yet. A rule, and a weak one. The needle is as sharp as before, and the poster works only on the person who looks up at the right moment.
Needles whose point pulls back inside the moment they are used, so the sharp thing is gone when the hand goes near.
Right. That swaps the hazard for a safer one: the needle still works and the danger lasts a second instead of until the bin. Nobody has to remember anything.
Thicker gloves for everyone.
Not yet. Gear, the bottom rung. A thicker glove helps one person, while worn, and a needle goes through most gloves anyway.
Lesson complete
The best answer to a hazard removes it; protective gear comes last because it guards one person, while worn.